For many years, busbar assemblies, such as those used in distribution boxes, have been used in a wide variety of domestic and industrial applications to provide a convenient means to supply relatively high electric currents (up to 5000 amps, for example). These assemblies are convenient from an electrical point of view and are relatively compact and easily accessible for maintenance purposes.
As shown in FIG. 7, prior art bolted busbar assemblies 200 have a conductive bar 240 with supports 250 at each end and contain multiple threaded through-holes 215 in which bolts 210 are positioned, which bolts 210 can be raised or lowered by loosening or tightening, respectively, in a conventional manner. A washer 220 or other retention device is generally provided intermediate the head of the bolt 210 and the conductive bar 250. Electrical cables 230 are then positioned on the bar 250 adjacent the bolts 210. When the bolts 210 are tightened, they descend into the through-holes 215. The bolt 210 is tightened until the washer 220 squeezes the cable 230 securely against the bar 240.
However, the through-holes 215 reduce current capacity by reducing the conductive cross-sectional area of the busbar 240. Furthermore, busbar assemblies are usually subjected to one or both of vibration and thermal stress during normal operating conditions. In conventional busbar assemblies 200, the bolts 210 have a tendency to loosen over time, reducing the clamping force on the cable 230 imparted by the washer 220. This can lead to interruptions in service and even the possibility that the cable 230 will slip from the assembly 200 and lose electrical contact entirely.
What is needed is a busbar assembly that overcomes these and other drawbacks found in current busbar assemblies.